A user equipment or an application program needs to frequently authenticate a user, so as to determine an identity of the current user. Authentication is a primary security barrier before the user is allowed to access data and an application in a terminal.
One of the most essential factors of a user authentication mechanism is a possibly low user memory price, which improves usability. In addition, the user equipment is always carried along by the user and used in various occasions and circumstances, and an authentication process is easily peeped at. Therefore, it is required that the authentication mechanism has a certain anti-peeping capability.